Effects of Waterlogging at Flowering Stage on the Grain Yield and Starch Quality of Waxy Maize

Waterlogging is a common abiotic stress in global maize production. Maize flowering stage (from tasseling to silking) is more fragile to environmental stresses, and this stage frequently overlapped the plum rain season in the middle and lower reaches of Yangtze river in China and affect the yield and quality of spring-sown maize severely. In the present study, the soil moisture content under control and waterlogging conditions at the flowering stage was controlled by a negative-pressure water supply and controlling pot device in a pot trial in 2014-2015. The grain yield, starch content, and starch structural and functional properties under two soil moisture levels were compared using Suyunuo5 (SYN5) and Yunuo7 (YN7) as materials, which are the control hybrids of National waxy maize hybrid regional trials in Southern China. The results observed that the grain yield was reduced by 29.1% for SYN5 with waterlogging due to the decreased grain weight and numbers, which was significantly higher than that of YN7 (14.7%), indicated that YN7 was more tolerant to waterlogging. The grain starch content in YN7 was decreased by 9.4% when plants suffered waterlogging at the flowering stage, whereas the content in SYN5 was only decreased in 2014 and unaffected in 2015. The size of starch granules and proportion of small-molecule amylopectin with waterlogging at the flowering stage increased in SYN5 and decreased in YN7 in both years. The type of starch crystalline structure was not changed by waterlogging, whereas the relative crystallinity was reduced in SYN5 and increased in YN7. The pasting viscosities were decreased, and the pasting temperature was unaffected by waterlogging in general. The gelatinization enthalpy was unaffected by waterlogging in both hybrids in both years, whereas the retrogradation enthalpy and percentage in both hybrids were reduced by waterlogging in 2014 and unaffected in 2015. Between the two hybrids, YN7 has high pasting viscosities and low retrogradation percentage than SYN5, indicated its advantages on produce starch for more viscous and less retrograde food. In conclusion, waterlogging at the flowering stage reduced the grain yield, restricted starch accumulation, and deteriorated the pasting viscosity of waxy maize. Results provide information for utilization of waxy maize grain in food production.

Engineered extracellular vesicles mediated CRISPR-induced deficiency of IQGAP1/FOXM1 reverses sorafenib resistance in HCC by suppressing cancer stem cells

BACKGROUND

Sorafenib resistance poses therapeutic challenges in HCC treatment, in which cancer stem cells (CSCs) plays a crucial role. CRISPR/Cas9 can be utilized as a potential technique to overcome the drug resistance. However, a safe, efficient and target specific delivery of this platform remains challenging. Extracellular vesicles (EVs), the active components of cell to cell communication, hold promising benefits as delivery platform.

RESULTS

Herein we report the normal epithelial cell -derived EVs engineered with HN3(HLC9-EVs) show competing tumor targeting ability. Anchoring HN3 to the membrane of the EVs through LAMP2, drastically increased the specific homing of HLC9-EVs to GPC3⁺Huh-7 cancer cells rather than co-cultured GPC3^-LO2 cells. Combination therapy of HCC with sorafenib and HLC9-EVs containing sgIF to silence IQGAP1 (protein responsible for reactivation of Akt/PI3K signaling in sorafenib resistance) and FOXM1 (self-renewal transcription factor in CSCs attributed to sorafenib resistance), exhibited effective synergistic anti-cancer effect both in vitro and in vivo. Our results also showed that disruption of IQGAP1/FOXM1 resulted in the reduction of CD133⁺ population that contribute to the stemness of liver cancer cells.

CONCLUSION

By reversing sorafenib resistance using combination therapeutic approach with engineered EVs encapsulated CRISPR/Cas9 and sorafenib, our study foreshadows a path for a better, accurate, reliable and successful anti-cancer therapy in the future.

Efficacy and Safety of Tocilizumab Treatment COVID-19 Patients: A Case-Control Study and Meta-Analysis

INTRODUCTION

As the pandemic progresses, the pathophysiology of COVID-19 is becoming more apparent, and the potential for tocilizumab is increasing. However, the clinical efficacy and safety of tocilizumab in the treatment of COVID-19 patients remain unclear.

METHODS

To assess the efficacy and safety of tocilizumab treatment in COVID-19 patients, we performed a retrospective case-control study. The study was conducted, including 95 patients treated with tocilizumab plus standard treatment and matched controls with 95 patients treated with standard treatment therapy by propensity score from February to April 2020. We searched some databases using the search terms for studies published from January 1, 2020, to June 1, 2021.

RESULTS

Our case-control study found a lower mortality rate in the tocilizumab treatment group than in the standard treatment group (9.47% versus 16.84%, P = 0.134), but the results were not statistically significant. We also found that the mortality rate in tocilizumab treatment groups was significantly lower than in the standard treatment group in the stratified ICU analysis (OR 0.52, 95% CI 0.44-0.61, P = 0.048 and OR 0.31, 95% CI 0.10-0.99, P = 0.044). We selected 49 studies (including 6568 cases and 11,660 controls) that met the inclusion criteria in the meta-analysis. In the overall analysis, we performed a meta-analysis that showed significantly decreased mortality after patients received tocilizumab (OR 0.81, 95% CI 0.69-0.95, P = 0.008). We also revealed significant associations within some subgroups. The sequential trial analysis showed a true-positive result. No significant associations were observed between tocilizumab and elevated secondary infection risk, discharge, adverse events, and mechanical ventilation in the overall analysis.

CONCLUSION

Tocilizumab significantly decreased mortality in COVID-19 patients with no increased discharge, secondary infection risk, adverse events, and mechanical ventilation in a meta-analysis. Our data suggest that clinicians should pay attention to tocilizumab therapy as an effective and safe treatment for COVID-19 patients.